Pain Management Wrap-Up Chronic Care David Tauben, MD Medicine Anesthesia & Pain Medicine
Objectives Understand that Pain is Complex Know how to select Rx based on Pain type Be aware that Rx only reduces pain 30-50% Recognize that Chronic Pain IS NOT prolonged Acute Pain Be able to: Convert any opioid to Morphine Equivalent Dose Set up a correctly dosed PCA Conduct an Opioid Trial Interpret a UDT
The Experience of Pain 1 part Nociception 3 parts Psychosocial
Acute Pain Chronic Pain Chronic Pain changes the brain Chronic opioids change biopsychosocial response Tolerance Withdrawal Opioid induced Hyperalgesia Depression Disability Chronic use entails more complex concerns Addiction and Physiologic dependence Risks increase with duration and dose Adverse effects Aberrant behavior
3 Pain Types Incidental Activation of nociceptors without tissue damage Nociceptive Injury (trauma, inflammation, tumor, etc) with maintained activation of peripheral pain receptors Complex hypernociceptive milieu Neuropathic/Central Typically initiated by peripheral tissue or nerve injury Injury is no longer required to maintain pain Symptoms: Paresthesias Signs: Allodynia, Cumulative summation
Pharmacologic options: by Pain Type Nociceptive Rx: Neuropathic Rx: Acetaminophen & other NSAIDs (Cox 1-3) Corticosteroids Opioids TCAs (probably) AEDS (maybe) TCA and SNRI Antidepressants Antiepileptics Opioids Best Rx can do is 30-50% improvement in VAS/NRS report Need brain retraining with non-medication treatment
Evaluate 6 Pain Treatment Domains 1. Pain Intensity (VAS/NRS) 2. Physical Functioning 3. Emotional functioning 4. Global improvement 5. Symptoms and adverse effects 6. Disposition: compliance/adherence
Opioid dose conversions Equivalency Dosing Morphine 30 mg * Codeine 200 mg Fentanyl (TD) 12.5 Hydrocodone 30 mg Hydromorphone 6 mg Oxycodone 20 mg Oxymorphone 10 mg * MS IV = PO MS x 2 Methadone in MEDs Pharmokinetically Logarithmic Methadone Dosage <30 mg = 3-4 x Morphine 30-40 mg = 4-6 x MS 40-60 mg = 10 x MS >60 mg = 12 x MS WA AMDG Opioid Calculator www.agencymeddirectors.wa.gov
MED dose converter AMDG on-line tool www.agencymeddirectors.wa.gov
Transition to Chronic Opioid Therapy Occurs at ~ 90 days Make explicit: Likely committed to life-long opioids Side-effect management: Driving risks OD risks Abstinence syndrome Sleep apnea Hypogonadism Informed consent agreement Urine Drug Test
Dose Limits for Non-Palliative Care Increase in risk of overdose per year compared to MED dose 10 9 8 7 6 5 4 3 2 1 0 <20 mg MED 21-99 mg MED >100 mg MED Dunn KM, Saunders KW, Rutter CM, Banta-Green CJ, Merrill JO, Sullivan MD, Weisner CM, Silverberg MJ, Campbell CI, Psaty BM, Von Korff M, Opioid prescriptions for chronic pain and overdose. Ann Intern Med. 2010;152:85-92
Washington State Agency Medical Directors Group: Interagency Guideline on Opioid Dosing for Chronic Non-cancer Pain * www.agencymeddirectors.wa.gov/guidelines.asp Take a breath at 90 mg MED Take 5 before exceeding 120mg/day MED dose threshold: No pain management consultation needed if the prescriber is documenting sustained improvement in both function and pain. Consider specialty consultation if frequent adverse effects or lack of response is evident to address: Evidence of undiagnosed conditions Presence of significant psychological condition affecting treatment Potential alternative treatments to reduce or discontinue use of opioids Risk and benefit of a possible trial with opioid dose >120 mg/day MED *Does NOT apply to Pailliative and End of Life Care
Opioid Trial Intention to assess opioid responsiveness Analgesia Activity Adverse effect Aberrant behavior Intention to discontinue (or reduce) when benefits risks Opioid Rotation When side-effects occur Possibly when Opioid Non-Responsive The man (or woman) who is going down the wrong path who turns around first is making the most progress C.S. Lewis
Natural Opiates: Metabolism
Monitoring Urine Drug Testing NIDA-5 : Misses oxycodone, methadone, benzodiazepines! Dipstick vs. Gas Chromatography (GC): confirmation testing Metabolic pathways Codeine Morphine Codeine Hydrocodone Hydromorphone Morphine Hydromorphone Interpretation of negatives/positives Compliance measurement
Problem 1: MED Conversion Oxycontin 40 TID + Fentanyl 75 mcg + Hydrocodone 7.5/750 2 QID 120 x 1.5 = 180 + 75 x 2.5 180 + 7.5 x 8 x1:1 = 60 = 420 MED
Problem 1a: PCA Set-up Oxycontin 40 TID + Fentanyl 75 mcg + Hydrocodone 7.5/750 2 QID = 420 MED Morphine IV PCA: (PO dose = IV dose) 3 Total IV MED = 140 Basal/hr = total/24 hr: 5.6 (round down) = 5mg/hr Dose: 5 mg x 2 = 10 mg Hydromorphone PCA Hydromorphone = MS 4 Basal/hr: 5/4= 1.25 mg/hr Dose: 0.2 mg x 10 = 2 mg
Problem 2: Opioid Trial Short-acting Rx options: Hydrocodone ±cmpd, Oxycodone ± cmpd, Morphine, Hydromorphone Long-acting Rx options: MS ER, Oxycontin, or Methadone, occas. Fentanyl topical Measure/Record: A: A: A: A: Analgesia Activity Adverse Effects Aberrant Behavior Duration: 90 days Calculated MED: 120 mg Assessment: Benefits > Risks? Taper schedule if indicated: 10% reduction per week
Problem 3: Interpreting UDT Rx ing Oxycontin and hydrocodone Find: Benzodiazepine, Amphetamines, Oxymorphone, Hydromorphone What s aberrant? Benzo and Amphetamines What do you do now? Confirm amphetamines by reflex testing (low specificity); determine significance/source of benzo